Blue Screen of Death, Hardware problem?

I have been doing some upgrades on my PC ( MOBO, CPU, PSU, DVD-R)
After I had installed all these things, the computer would run fine, at first. but at times when I try to install something, it will start out fine, then freeze up for a second and all of a sudden I see a evil blue screen, you can only see it for a total of three seconds. The only things im able to see are "Hardware" and " Pysical memory dump" then restart.
So I figured it must be the Hard Drive if its only happening when im installing. So I buy a new HD and bought Vista while I was at it. So now I think my blue screen problem was over with, I was wrong. But this time I wasnt installing, I was trying to open up something.

Vista takes up alot of memory, could this problem be from my memory maxxing out and failing?
Any help would be appreciated, so i dont go spending money on things I dont need.